Capacity Enhancement in CDMA Cellular Networks using Multi-hop Communication

The Multi-hop CDMA cellular concept has been proposed to overcome cellular drawbacks, like congestion and load imbalance. Although it is a widely accepted that multi-hopping increases cellular capacity, it has never been quantified. In this paper, the capacity increase in multi-hop CDMA cellular networks is quantified. To this end, and since CDMA networks are interference limited, we derive equations for interference in multi-hop cellular networks at base stations (BSs) and relaying mobile terminals (MTs) in the uplink. The interference formulas are used to verify that capacity can be increased, by increasing either the number of simultaneous calls or data rate. A 10% increase in the number of simultaneous calls is shown to be possible even under worst-case scenarios. This increase is achievable while keeping interference at relaying MTs below acceptable thresholds. The novelty of this paper is that it quantifies, and for the first time, interference levels at MTs and BSs as well as potential capacity enhancements.